Mechanical tests (pack and system)¶

Five mechanical tests apply to battery packs and systems under GB 38031-2025. Four are revised from the 2020 edition; one (bottom impact) is new. All five share the universal pack/system observation period: 2 hours at test environment temperature after the test ends.

Clause	Test	Object	Status vs. 2020	Summary
8.2.1	Vibration	pack / system	revised (both)	Random + sine-dwell vibration on x/y/z. Per-axis PSD per Table 2 (non-M1/N1, 2 h/axis sine) or Table 3 (M1/N1, 1 h/axis sine).
8.2.2	Mechanical shock	pack / system	revised (req only)	Half-sine pulse, 7 g peak, 6 ms pulse width, ±z axis, 12 shocks total.
8.2.3	Simulated collision	pack / system	revised (req only)	Sled-cart pulse on x and y per Table 6 envelope, scaled by host vehicle curb weight (≤3.5 t / >3.5–<7.5 t / ≥7.5 t).
8.2.4	Compression	pack / system	revised (both)	Quasi-static crush at ≤2 mm/s, x and y, stop at 100 kN or 30 % deformation, hold 10 min. Pass criterion drops "no leakage" and "no housing crack".
8.2.16	Bottom impact	pack / system / vehicle	new	Hemispherical Ø 30 mm, 10 kg steel impactor, +z, 150 J ± 3 J, three manufacturer-defined risk points. N-class with ≥ 200 mm fully-loaded ground clearance: exempt.

Pass criteria for the first four tests follow the universal STD wording (no leakage / no housing crack / no fire / no explosion plus insulation ≥ 100 Ω/V DC, ≥ 500 Ω/V AC) — except compression (5.2.4), which drops the leakage and housing-crack requirement.